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We show a scheme for achieving high-speed operation for carrier-injection based silicon electro-optical modulator, which is optimized for small size and high modulation depth. The performance of the device is analyzed theoretically and a 12.5-Gbit/s modulation with high extinction ratio >9dB is demonstrated experimentally using a silicon micro-ring(More)
Mitochondria are sites of cellular energy production but may also influence life and death decisions by initiating or inhibiting cell death. Mitochondrial depolarization and the subsequent release of pro-apoptotic factors have been suggested to be required for the activation of a cell death program in some forms of neuronal apoptosis. We induced apoptosis(More)
Several kinds of nonlinear optical effects have been observed in recent years using silicon waveguides, and their device applications are attracting considerable attention. In this review, we provide a unified theoretical platform that not only can be used for understanding the underlying physics but should also provide guidance toward new and useful(More)
We propose the use of slow-light, band-edge waveguides for compact, integrated, tunable optical time delays. We show that slow group velocities at the photonic band edge give rise to large changes in time delay for small changes in refractive index, thereby shrinking device size. Figures of merit are introduced to quantify the sensitivity, as well as the(More)
We demonstrate highly broad-band frequency conversion via four-wave mixing in silicon nanowaveguides. Through appropriate engineering of the waveguide dimensions, conversion bandwidths greater than 150 nm are achieved and peak conversion efficiencies of-9.6 dB are demonstrated. Furthermore, utilizing fourth-order dispersion, wavelength conversion across(More)
The propagation of 300 femtosecond optical pulses in Silicon-on Insulator waveguides has been studied by means of a pump-probe set-up. The ultrafast pulses allowed the observation of large Kerr-induced red and blue shifts (9nm and 15nm, respectively) of the probe signal depending on the delay between pump (1554nm) and probe (1683nm) pulses. A numerical(More)
We demonstrate amorphous and polycrystalline anatase TiO 2 thin films and submicrometer-wide waveguides with promising optical properties for microphotonic devices. We deposit both amorphous and polycrystalline anatase TiO 2 using reactive sputtering and define waveguides using electron-beam lithography and reactive ion etching. For the amorphous TiO 2 , we(More)
We demonstrate high quality factor etchless silicon photonic ring resonators fabricated by selective thermal oxidation of silicon without the silicon layer being exposed to any plasma etching throughout the fabrication process. We achieve a high intrinsic quality factor of 510,000 in 50 µm-radius ring resonators, corresponding to a ring loss of 0.8 dB/cm.(More)
Slot waveguides allow for high optical confinement in a planar optical waveguide. Here we show a method for maintaining this high degree of confinement in slot waveguides with sharp bends. This high confinement can be achieved by using an asymmetric slot-based structure, where the mode in the bend remains localized in the slot region. We show that the(More)
Recently researchers have demonstrated ultra high quality factor (Q) resonances in one-dimensional (1D) dielectric gratings. Here we theoretically investigate a new class of subwavelength 1D gratings, namely " diatomic " gratings with two nonequivalent subcells in one period, and utilize their intrinsic dark modes to achieve robust ultra high Q resonances.(More)